Device for spray applying mold-release agent to a die casting mold

Abstract

A mold-release agent injection nozzle is provided in the portion of the die casting machine leading to the mold cavity or in the mold. A mold-release agent is then spray applied to the surfaces of the mold through the nozzle while the mold is closed. The surplus mold-release agent is then discharged through a vent port having a displaceable valve.

What is claimed is: 
     
       1. An appparatus for spray applying a mold-release agent to surfaces of a mold of a die casting machine that are contacted by molten metal, said mold defining a mold cavity, said apparatus comprising: a mold-release agent injection nozzle through which a mold-release agent is injected;   a plunger sleeve connecting said injection nozzle to said mold cavity;   a vent channel connected to said mold cavity for permitting release of excess mold-release agent from said mold cavity through a vent port; and   a positively driven vent valve means for selectively sealing said vent channel, said vent valve means comprising a double-acting piston/cylinder having a cylinder, a piston mounted in the cylinder for reciprocal movement, and a piston rod connected to the piston and projecting out through the cylinder, said piston rod being movable between a closed position to prevent communication between said vent channel and said vent port while a mold-release agent is spray applied to said surfaces of the mold with the mold closed and an open position to permit release of excess mold release agent from the vent channel.